The present invention relates to methods and apparatus for detecting heat sources; more particularly, methods and apparatus for detecting forest fire ignition sources.
There are several stages in wild fire (forest fire) suppression and control activities. These stages include but are not limited to preparation, detection, suppression, and mop-up. The preparation stage might involve the strategic stockpiling of appropriate materials, the construction of fire roads, and controlled burns. Prompt and accurate detection of wild fires via human spotters, remote instrumentation and space-based sensors allows efficient suppression activity to be taken while the fire is still tractable. The suppression phase utilizes a coordinated mix of activities and technologies ranging from direct human efforts (Smokejumpers, etc.) to aerial water and/or fire retardant applications. The final mop-up phase insures that the contained and controlled fire is rendered harmless and does not re-ignite.
The last phase of the firefighting activity, mop-up, is critical. There are numerous cases where wild fires that were apparently contained and effectively suppressed have re-ignited and grown to be a much larger problem than the original. Mop-up activities often must be undertaken when firefighting personnel and systems are highly stressed and exhausted by the suppression phase. One of the most immediate and important activities in the mop-up phase is xe2x80x9ccold-trailingxe2x80x9d. Cold-trailing is the careful inspection of the wild fire perimeter for potential re-ignition sources and the elimination of these sources. A single smoldering root concealed by a cover such as an ash layer or other debris has the potential to re-ignite the fire days or even weeks later.
The current practice of cold trailing requires, for example, that firefighting personnel carefully inspect a fifty foot band at the perimeter of a fire area or area of a recent fire. In some situations, the entire fire area may be inspected. The firefighter must carefully inspect those locations most likely to harbor hidden and sheltered ignition sourcesxe2x80x94e.g. under charred stumps or fallen logs. These potential ignition sources often have a cover such as a thick layer of ash and/or are not otherwise directly observable. Current cold-trailing practice requires that the firefighters manually reach into these possible ignition sources and feel for heat with his or her bare hand. It is fairly obvious that this activity exposes the firefighter to the very real probability of burnt fingers or hands. In addition, adequate inspection of likely ignition locations can require significant physical activity such as stooping, bending, and stretching. The quality and effectiveness of the cold-trailing effort is directly impacted by the discomfort and effort a firefighter must expend to perform this activity.
Clearly, there is a need for a tool that allows the cold-trailing activity to be performed both more effectively and with less risk or discomfort for the firefighter. In addition, there is a need for methods and apparatus that can significantly accelerate the cold-trailing activity while increasing the likelihood that covered or otherwise concealed ignition sources will be located and eliminated.
This invention seeks to provide methods and apparatus that can overcome deficiencies of known fire fighting procedures. Practicing this invention makes it possible to perform fire fighting activities such as detecting fire ignition sources and assessing fire hazard more rapidly, more accurately, and more safely than is usually possible with the standard fighting procedures.
One aspect of the present invention is a method of looking for potential forest fire ignition sites. In one embodiment, the method includes the step of probing potential sites with an electronic temperature sensor. The method further includes measuring at least one of temperature and rate of rise of temperature so as to determine the potential fire hazard and providing a signal of the fire hazard based on the measurements. Next, the method includes repeating the previous steps at each new potential site.
Another aspect of the present invention is an apparatus for probing concealed potential fire ignition sites and detecting a fire hazard. In one embodiment, the apparatus includes a temperature sensor comprising a temperature sensitive element for providing an electrical signal proportional to temperature or an electrical signal proportional to a change in temperature. The apparatus also includes an electronic circuit electrically connected with the sensor so as to receive the electrical signal from the sensor. The circuit is capable of deriving at least one of a temperature and a rate of temperature rise using the signal from the sensor, and the circuit is capable of converting the signal from the temperature sensor into a second signal for at least one of an audible indication and a visual indication. Also included in the apparatus is an elongated member having a first end and a second end. The temperature sensitive element is attached to the member and positioned near the second end of the member.
When using the apparatus, a fireman or other person can hold the member near the first end and position the sensor in or near the potential fire ignition sites so that the sensor and the circuit can determine the fire hazard.
Another aspect of the present invention is a method performed in an electronic device such as a microprocessor for electronically identifying fire hazards at potential fire ignition sites. The electronic device is used in combination with a temperature sensor. The method includes the steps of: a) acquiring signals from the temperature sensor; b) converting the signals into digital information representing at least one of a temperature, a rate of rise of temperature, and a temperature gradient; c) comparing the signals to at least one reference parameter to identify a fire hazard; d) providing a command to indicate a fire hazard when a fire hazard is identified in step c; and e) reducing power consumption of the microprocessor after a predetermined period of time.
It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out aspects of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
The above and still further features and advantages of the present invention will become apparent upon consideration of the following detailed descriptions of specific embodiments thereof, especially when taken in conjunction with the accompanying drawings.